1 // PR c++/48449
2 // { dg-do compile { target c++11 } }
3 
4 template<class T, class = decltype(T())>
5 char f(int);
6 
7 template<class>
8 char (&f(...))[2];
9 
10 struct A { virtual ~A() = 0; };
11 
12 static_assert(sizeof(f<int&>(0)) != 1, "Error");
13 static_assert(sizeof(f<void()>(0)) != 1, "Error");
14 static_assert(sizeof(f<A>(0)) != 1, "Error");
15